Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933271AbcDKODy (ORCPT ); Mon, 11 Apr 2016 10:03:54 -0400 Received: from mx2.suse.de ([195.135.220.15]:37397 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932221AbcDKNXp (ORCPT ); Mon, 11 Apr 2016 09:23:45 -0400 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, David Vrabel , Konrad Rzeszutek Wilk , Jiri Slaby Subject: [PATCH 3.12 07/98] xen-netback: don't use last request to determine minimum Tx credit Date: Mon, 11 Apr 2016 15:22:09 +0200 Message-Id: <65566f8f9222333adfb85d4f676aa40b53ed6177.1460380917.git.jslaby@suse.cz> X-Mailer: git-send-email 2.8.1 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1529 Lines: 41 From: David Vrabel 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit 0f589967a73f1f30ab4ac4dd9ce0bb399b4d6357 upstream. The last from guest transmitted request gives no indication about the minimum amount of credit that the guest might need to send a packet since the last packet might have been a small one. Instead allow for the worst case 128 KiB packet. This is part of XSA155. Reviewed-by: Wei Liu Signed-off-by: David Vrabel Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Jiri Slaby --- drivers/net/xen-netback/netback.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index a1186533cee8..d4a1db9fb224 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -695,9 +695,7 @@ static void tx_add_credit(struct xenvif *vif) * Allow a burst big enough to transmit a jumbo packet of up to 128kB. * Otherwise the interface can seize up due to insufficient credit. */ - max_burst = RING_GET_REQUEST(&vif->tx, vif->tx.req_cons)->size; - max_burst = min(max_burst, 131072UL); - max_burst = max(max_burst, vif->credit_bytes); + max_burst = max(131072UL, vif->credit_bytes); /* Take care that adding a new chunk of credit doesn't wrap to zero. */ max_credit = vif->remaining_credit + vif->credit_bytes; -- 2.8.1